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6 years, 8 months ago.
How to read the data received by Bluetooth
Hi. If I send two characters at a time to Bluetooth, but the getc () function can only read one character at a time, how can I read the data that Bluetooth receives without causing data loss? Thanks.
Question relating to:
1 Answer
6 years, 8 months ago.
Hello Zhang,
You could try to setup suitable Rx buffer and receive data in a while
loop in main . With NUCLEO-F072RB for example as below:
#include "mbed.h" #define RX_MAX 10 Serial pc(USBTX, USBRX); Serial bt(PB_6, PA_10); int main(void) { char rxBuf[RX_MAX]; int i = 0; bool rxBufOverflow = false; pc.baud(115200); bt.baud(115200); pc.printf("Ready to receive data over Bluetooth.\r\n\r\n"); while (1) { while (bt.readable()) { if (i < RX_MAX) rxBuf[i++] = bt.getc(); else { bt.getc(); rxBufOverflow = true; } } if (i > 0) { printf("Data received:"); for (int j = 0; j < i; j++) printf(" 0x%.2x", rxBuf[j]); printf("\r\n"); if (rxBufOverflow) { printf("Error: Rx buffer overflow -> Some data lost!\r\n"); rxBufOverflow = false; } printf("\r\n"); i = 0; } } }
Or receive data in a while
loop using interrupt service routine:
#include "mbed.h" #define RX_MAX 10 Serial pc(USBTX, USBRX); Serial bt(PB_6, PA_10); char rxBuf[RX_MAX]; volatile int i = 0; volatile bool rxBufOverflow = false; void onBluetoothReceived(void) { while (bt.readable()) { if (i < RX_MAX) rxBuf[i++] = bt.getc(); else { bt.getc(); rxBufOverflow = true; } } } int main(void) { pc.baud(115200); bt.baud(115200); bt.attach(&onBluetoothReceived, Serial::RxIrq); pc.printf("Ready to receive data over Bluetooth.\r\n\r\n"); while (1) { if (i > 0) { printf("Data received:"); for (int j = 0; j < i; j++) printf(" 0x%.2x", rxBuf[j]); printf("\r\n"); if (rxBufOverflow) { printf("Error: Rx buffer overflow -> Some data lost!\r\n"); rxBufOverflow = false; } printf("\r\n"); i = 0; } } }